Pipe racking apparatus



Dec. 11, 1956 Y I F. D. DE JARNETT 2,773,605

PIPE RACKING APPARATUS Filed Nov. 12, 1953 6 Sheets-Sheet l y 1956 F. D. DE JARNETT 2,773,65

PIPE RACKING APPARATUS Filed Nov. 12, 1953 6 Sheets-Sheet 2 Dec. 11, 1956 F. D. DE JARNETT PIPE RACKING APPARATUS 6 Sheefs-Sheet 3 Filed NOV. 12, 1953 Dec. 11, 1956 F. D. DE JARNETT 2,7?3, 5

PIPE RACKING APPARATUS 6 Sheets-Sheet 4 Filed Nov. 12, 1953 62 INVENTOR.

Dec. 11, 1956 F. D.DE JARNETT 2,773,605

PIPE RACKING APPARATUS Filed Nov. 12, 1953 6 Sheets-Sheet 5 Zun Ax 24 Dec. 11, 1956 F. D. DE JARNETT 2,773,505

PIPE BACKING APPARATUS Filed Nov. 12, 1953 6 Sheets-Sheet 6 45 v o o o "I o "g o Q3 0 o o o g o I G0 4.3 o o o o g i o I o O 0 O O i O o o o o g g I o o i o o o 5' o o i o o o o 8 o o INVENTOR. v fkmvz Q fisJnen srr United States Patent 2,773,605 PiPE'RAcK' IN "G APPARATUS- Franlr D. De Jarnett, Barcelona, Venezuela, assignor of one-half to Paul A. Medearis xiipiitation November 1'2, 1953, semi No. 391,682 33 Claims. (Cl. 214-45 This invention relates to devices for handling pipe at an oilwell and more particularly pertains to apparatus for racking sections or stands of pipe.

In oil well drilling operations, a drill stem or string of drill pipe is progressively lowered into the well bore by adding successive sections or stands of pipe to the upper end of the string and the drill stem is withdrawn progressively by removing successive sections or stands of vpipe from the upper end. The sections or stands of pipe that are out of the well bore are stored or racked in a manner to make them readily available for reassembly to the drill stem. The drill stein must be assembled and disassembled in this manner repeatedly in the course of drilling an oil well for the purpose of changing drill bits and for other purposes. Since actual progress in drilling must be suspended at such times, it is highly desirable to carry out the procedure with the greatest rapidity.

The general object of the invention is to provide poweractuated apparatus for racking stands of pipe of any desired length in upright position and in an orderly and expeditious manner with minimum labor cost. A further object is to provide such apparatus that is largely automatic for simplified operation and control of the apparatus.

With a power-actuated racking apparatus having automatic features, the time required to change a drill bit'may be drastically reduced 'andQinaddition, thecrewrequired for theoperation may be greatly reduced. Under prevail ing practices, a minimuincrew of five me'nis required but the apparatusof the invention makes it possible to reduce this minimum to two men, namely, the driller and the operator of the racking apparatus.

Broadly described, the objects of the invention are attained by a plurality of'power-actuated lower support units to'support the lower ends of the stands of'pipe, in combination with a corresponding plurality of power-actuated upper rack units to engage upper portions of the stands, each pair of lower and upper units holding one row of pipe. Each unit has one end adapted either to receive'pipe withdrawn from the well bore or to relinquish pipe that is to be returned to the 'we'llb'orefa'nd each unit is adaptedto shift "the stands of pipe successively from said'receiving end to the opposite end and vice versa. Thus, a row'of pipe may be accumulated "progressively by feeding successive stands of 'pipe't'o therece'iving ends of a'p'air of lower and upper units, and, subsequently, the 'row of pipe may be unracked progressively by successive removal of the stands of pipe from the same ends of the units.

To'rack pipe in such pluralities of'paired lower and upper units and subsequently tounrack the pipe,'it is merely nece'ssary to'provide meansto shift thepipe back and forth between the region of the axis of the well bore and the'rec'eivingends of the cooperating pairs ofupper and lower units. Various expedients may be used for this purpose in various practices of the invention. v v

"For example,'thefcornbination disclosed in my'Patent 2,643,005 "(which is herebyincluded in thepreserit dis- 2,773,605 Patented Dec. 11, 1956 "cl'osureby reference), may be used to shift stands of pipe back and forth between the region of the axis of the well bore and the'receiving ends of the cooperating pairs of 'units. This combination comprises a laterally shiftable crown block, a stabilizer and a transfer crane. The crown block is first aligned with the axis of the well bore to lift pipe from the bore and then is shifted laterally away from the axis for the down trip of the elevator. In pulling a drill stem, the stabilizer holds the elevated stand of pipe released by the elevator with the stand positioned substantially on the axis of the well bore and the transfer crane shifts the stand from this position to a stored or racked position while the traveling crown block is moving downward to lower the elevator. In like manner, in reassembling the drill string, the transfer crane shifts the racked stands of pipe laterally "out of racked positions to the stabilizer for joining to the drill stern and for subsequent engagement by the elevator to lower the drill stem. The crown block takes a position on the axis of the well here for lowering the drill stem into the well bore and shifts laterally away from the axis for the return upward trip of the elevator, thus avoiding interference with the concurrent functioning of the stabilizer and transfer crane.

In the preferred practice 'of the present invention, 1 simplifythe problem of transferring pipe to and from the reee'ivin'g ends of the cooperating .pairs of lower and upper units by providing power means to move the units relative to a position or station conveniently near the axis of the well bore. Thus the cooperating pairs of the lower and upper unit's move successively to a station for receiving or relinquishing pipe and this station is so close to the axis or the well bore that'only relatively simple means is required to shift stands of pipe back and forth between the station and the well bore axis. A further object of the preferred practice of the invention is to vprovide such pipe shifting means.

The various features,"objects and advantages of the inv'e'nti'o'n will b'e'understo'od from the following detailed description of the presently preferred practice of the invention, this description bei'n g considered with the accompanyin'g drawings. I

In thedrawin'gs, which are to be regarded as merely illustrative:

Fig, 1 isj'a side elevation of'the lower portion ofanoil well derrick illustrating the preferred practice of the invention;

Fig. 2 is'a similar elevation as viewed from the line 2 2 of Fig. "1;

Fig. 3 is a view of one of the lower support units, .the view being partly in section and partly in side elevation;

Fig. "4 is an-elevation of the plurality of lower support units as viewed in the direction of the arrow 4 of Fig. 3;

Fig. Sis 'a plan view of ajportion of a lower support unit, the portion being indicated'by the arrow-5 in Fig. 3;

Fig. 6'is a. plan view of one of the upper rack units together with "an associated pipe shifting means;

Fig. 7 'isj'a fragmentary view similar-to Fig. 6 showing the mechanisma't a different stage of operation;

Fig. 8 "is a 'si'r nilar fragmentary view illustrating the manner in whichthetpipe shifting meanscooperates with some of the operating upper rack unit;

Fig. 9 is an enlarged fragmentary view showing an auxiliary retractable partassociated with the operation of the pipe shifting means;

Fig. 10 is a transverse section on an enlarged scaleof aportion'of' thelpipeshifting means taken as indicated by' the line101'0 of Fig. 6;

Fig. 11 is a perspectiveview of selectedparts of the apparatus showing a'cooperating pair of lower and upper units and associated'means for'shifting stands of pipe 3 between the receiving ends of the two units and the region of the axis of the well bore;

Fig. 12 is a side elevation of the plurality of upper rack units and the pipe shifting means that cooperates therewith;

Fig. 13 is an elevation of the same upper rack units and associated pipe shifting means viewed as indicated by the arrow 13 in Fig. 12;

Fig. 14 is a plan view of the plurality of .lower support units; and

Fig. 15 is a plan view of the upper rack units together with the pipe shifting means associated therewith.

General arrangement Figs. 1 and 2 show an oil well with the usual derrick 20 having the usual elevated catwalk 21. Fig. 1 shows the usual housing 22 for the power plant that actuates the rotary drill and adjacent thereto shows a panel 23 on a control cabinet 24 for the convenience of the operator of the racking apparatus of the present invention. Also shown in Figs. 1 and 2 is an elevator 28 suspended in the usual manner from a traveling block 29.

It is contemplated that the elevator 28 will be of the power-actuated type, that is remotely controlled from the derrick floor. Preferably the elevator 28 and the associated traveling block 29 will be constructed as taught in my co-pending application Serial Number 245,898, entitled, Power-Elevator for Oil Wells, filed September 10, 1951, and now Patent No. 2,684,166 (which prior disclosure is hereby included in the present disclosure by reference). In accord with that disclosure, the movement of the traveling block 29 relative to the cable 30 stores power in the form of compressed air and the compressed air is transmitted to the elevator 28 through an air hose 31 for actuation of the elevator under remote control.

At a low level inside the derrick 20 is a plurality of lower support units 32 each of which is capable of supporting a row of stands S of pipe, there being in this instance eight stands per row. Each of the stands S of pipe is shown as comprising three lengths or sections of pipe 33 screwed together.

As best shown in Fig. 11, each of the lower support units 32 may have a series of support elements 34 pivotally interconnected by pins 35 in the manner of a sprocket chain. Each support element 34 may be provided with a conical boss 36 to enter and thereby engage the lower end of a stand of pipe. Fig. 11 shows in full lines a stand S on the first support element 34 at what may be termed the receiving end of the support unit. This is the end of the support unit 32 at which stands of pipe are received successively from the well bore in the course of withdrawing the drill stem and also is the end atwhich the racked stands of pipe are relinquished successively for return to the well bore in the procedure of reassembling the drill stem. When a stand S of pipe has been received by a support element 34 at the receiving end of a support unit 32, the chain of support elements is advanced one step away from the receiving end to bring the next support element in position to receive the succeeding stand of pipe. In this manner, each of the lower support units 32 is loaded progressively to accumulate a complete row of the stands of pipe. Subsequently, the stands of pipe of the row are unloaded from the support unit in a similar step-by-step manner, the chain of support elements being shifted towards the receiving end of the support unit one step each time a stand of pipe is removed from the receiving end.

At a higher level on the derrick, in this instance at approximately the level of the catwalk 21, is a plurality of upper rack units 40 corresponding to the lower support units 32, there being one upper rack units paired with each lower support unit to cooperate therewith in the racking of one row of the stands of pipe.

As shown in Fig. 6 each of the upper rack units 40 has aseries of pipe-engaging members 41 in the form of curved fingers to engage the individual stands of pipe. The curved fingers 41 are carried by a sprocket chain 42. In racking pipe in the course of pulling a drill stem, each succeeding stand of pipe is shifted to the receiving end of a rack unit 40 and the sprocket chain 42 of the unit is advanced one step to cause one of the fingers 41 to engage the newly presented stand of pipe. Thus each of the upper rack units 40 is loaded and unloaded progressively in similar manner to the corresponding lower support unit 32.

As heretofore indicated, preferably the problem of transferring pipe from the region of the axis of the well bore to the receiving ends of the cooperating pairs of lower and upper units is simplified by providing for the two pluralities of units to be shifted in succession to corresponding receiving stations for racking or unracking a row of stands of pipe. For this purpose, all of the lower support units 32 may be moved in unison by means including a long screw 43 and the upper rack units 40 may be moved in unison by an upper pair of parallel screws 44.

Any suitable means may be provided for shifting the stands S of pipe back and forth between the region of the axis of the well bore and the receiving ends of a pair of units, with the receiving end of the lower unit at the lower receiving station and the receiving end of the upper unit at the upper receiving station. In the present embodiment of the invention, for example, what may be termed a guide chute 45 is provided to displace the lower ends of the stands of pipe from the region of the well bore axis' to the lower receiving station and what may be termed a pipe shifting means 50 is associated with the upper plurality of rack elements 40 to shift the upper portions of stands of pipe to the upper receiving station.

The guide chute 45 is a suitably inclined trough member supported by legs 51, the trough member being relatively wide at its upper end and narrowing somewhat at the lower end that is adjacent the lower receiving station.

The pipe shifting means 50 includes a box-like housing 52, best shown in Fig. 11, which ismounted on a cantilever beam 53 for longitudinal reciprocation thereon. The reciprocative housing 52 carries a pipe engaging means in the form of hook 55 which may be actuated by remote control to engage and release the successive strands of pipe. When the housing 50 is moved outward on the beam 53 to the dotted line position in Fig. 11, the hook 55 may be operated to engage a stand of pipe at th axis of the well bore and then the housing 50 may be retracted under power to draw the stand of pipe towards the upper receiving station for the upper rack units 40.

In a typical operation of the apparatus for racking stands of pipe in the course of withdrawing a drill stem from the well bore, the elevator 28 is used to lift the drill stem in the manner shown in Fig. 1 and when three sections of the drill pipe are above ground, the drill stem is engaged by slips in the usual manner to permit the exposed stand of pipe to be unscrewed. The stand of pipe released from the drill stem is then lifted by the elevator 28 to bring the lower end of the stand slightly above the guide chute 45'.

The pipe shifting means 50 is then extended to permit the hook 55 thereon to engage the suspended stand of pipe at the axis of the well bore and to displace the stand of pipe towards the two receiving stations. As the pipe shifting means 50 causes this lateral displacement of the stand of pipe, the elevator 28 is lowered to bring the bottom end of the stand of pipe into contact with the guide chute 45 and the lower end of the stand of pipe slides down the chute to be guided thereby. The lower end of the pipe slides into engagement with the conical boss 36 of the support element 34 at the re ceiving end of the particular lower support unit 32 that of the laterally moving stand of pipe approaches the.

upper rack of unit 40 at the receiving station; the sprocket chain 42 'ofthe rack unit is advanced onestep to cause one of the fingers 41 at the receiving end of the rack unit to engage the stand of pipe. The hook 55 of the pipe shifting means 50 is then released from the stand of pipe in preparation for repeating the cycle of operation to rack the next succeeding stand of pipe.

When a lower support unit 32 and the corresponding upper rack unit 40 are completely loaded with a row of stands of pipe in this manner, the lower screw 43 is actuated to bring the next empty lower support unit 32 to the lower receiving station and in like manner the upper pair of screws 44 are actuated to bring the next empty upper rack 40 to the upper receiving station.

The unraeking of the stands of pipe in the reassemblingof the drill stem is carried out by substantially thesarrie steps in reverse sequence. With the drill stem in the well bore supported by slips, the pipe shifting means '0 is retracted to the receiving end of an upper rack unit 40 at the upper receiving station and the hook- 55 is actuated to engage the stand of pipe. The sprocket ehain 42 of the rack unit is actuated one step to re lease the stand of pipe from the rack unit and simultane'o'usly the pipe shifting rri'eans 50 is extended outward to swing the upper end of the stand of pipe into the region of the axis of the well bore to permit the remotely controlledelevator'ls to engage the stand of pipe. The hook SS is then released from the stand of pipe and the elevator 28 is raised to bring the lower end of the pipe upward sufiicient to clear the guide chute 45. During this upward movement of the stand of pipe, the lower end of the stand rides frictionally up the guide chute so that the guide chute serves as means to stabilise the'suspende'd stand of pipe and to minimize the tendenc of the suspended stand to swing like ape'nduluni. The elevator 28 is then lowered-to'permit the stand of pipe is be screwed to the drill stern and is again lowered to Iow'e'r the drill stemin accord with the newly added pipe.

9 The lower support units As shown in Figs. 3,- 4 and 14; the plurality of lower support units 32 may be mounted on a'carriage; desig nated as a whole by numeral 60 which comprises a platforin 61 supported by a series of flanged wheels 62 on a. pair of rails 63. The path of the carriage 60 along the rails 63, relative to the bore hole of the well may be understood by reference to Fig.- 14 where it can Be seen that the carriage is movable to bring any one of the lower support units 32 into position at the lower receiving station adjacent the lower end of the guide chute 45. It will be noted that the receiving station is immediately adjacent th periphery of the rotary table 64 and is positioned radially across the table from the region of the drill stem 65 in the well bore.

' The previously mentioned screw 43 that centrols the movements of the plurality of lower support units 32 issu itably' journaled in a position extending longitudinal- 19 under the carria e s0 and is energized by a suitable motor 66(Fig. 2). On the under side of the carriage 66 is welded a threaded body 67 in engagement with the threads of the screw 43. The threaded body '67 serves as a traveling nut to control the position of the carriage.

Each ofthe series of linked support elements 34 earriedby each support unit3 2 is a Hat metal-body which,- as best shown in Fig. 5, is formed at one end with. a pair of relatively widely spaced ears 70 and is formed at the other end with two ears 71 at lesser spacing. The more widely spaced cars 70 at the end of each support element 34 straddles the less widely spaced ears 71 of thenext adjacent. support ele'ment, both pairs of ears engagingthe same connecting pin 35.- Preferably a sleeve -72 journaled on each pin 35' between the two innet. ea-rs .71. Thus the series of support elements 34 when form a continuous sprocket ehain with the conicalbosses 36 thei'een tiirned seaward. This "s'p'r'aatei eha'inis looped ai on'nd the paced heiago'nal sp Beket wheels 73 and .14 that are mounted a ienate 75 au t 16am twa parallel upright side plates 76. The side plates 76 are wel, d to the platform 61 and are interconnected by a plate 77 which serves as a support for the upper run of the series of interlinked support elements 34.

suitable arrangement may be provided for actua e ing the series of supporteleinents 34 on each lower sup;- port unit 32. For example, a motor 79 may be positioned adjacent the path of the carriage60, as shown iirFig. 14, and adapted to makerelea sable operative connection with the sprocket wheel 73 of I each support unit when the support unit is at the receiving station. For this purpose the shaft 75 that carries the hexagenal sp eeket wheel 73 or each g support unit 32 may be provided with a were wheel 80 (Figs. 3, 4 and s in mass with a worm gear 81. The bevel gear 81 is on one end of a short shaft 82 jo'urnaled in a bearing 83 on the side of the lower support unit and the other end of this small shaft forms a ribbed clutch socket 84 to receive and cooperate afc'onic'al clutch membei 85 on the end of a drive shaft 86. The drive shaft 86 extends horizontally from the motor 79 and is adapted to shift longitudinally between aret'r 'acted disengaged position shown in full lines in Fig. 3 and an extended position shown in full lines in Fig. 5 at which "extended position the conical cluteh ni'e'm'ber is engaged in the clutch socket 84 to aetuate the hexagonal sprocket wheel 73 and thereby actuate the series of interlinked support elements 34.

The tippr rack units The plurality of upper rack units 40 are arranged in a first pper row pivotally mounted'on the upper serew 44 and a second lower row pivotally mounted on the lower screw 44, the rack units being freely pivotal without engagement with the threads of the screws. Positioned on substantially the same level as the upper screw 44 and parallel thereto is a fixed rod 90 to support a series of power cylinders for the upper row of rack units an'clin like manner a second fixed rod 90 is positioned parallel to the lower screw to carry a second series of power cylin ders for the lower row of rack units. I

As best shown in Figs. 11 and 12, eaeh of the power eylinders 91 is formed with an integral supporting bracket 92 that is slidingly mounted on one of the fixed rods 90. Each power cylinder has a forwardly extending piston rod 93 which is pivotally connected to an integral wing 94 of the corresponding rack 40 so thatextension and retraction of the piston rod willlswing the rack unit between a horizontal racking position and a substantially vertical idle position. As maybe seen in Fig. 12, the rack units of the upper row on the upper screw 44 swing upward to their retracted idle positions and the rack units of the lower row swing downward to their retracted idle positions. A

The rack units 40 of the upper row are confined laterally by whatmay be termed a carriage assembly and in like manner the rack units of the lower row are confined by a second carriage assembly. Each of the two carriage assemblies includes a series "of sleeves 95 on the corresponding screw 44 spacing the ack units apart and a corresponding plurality of sleeves 96 on the associated fixed rod 90 to serve as spacers for the corresponding power cylinders. At each end of each carriage assembly is an end member 97 having apertures to receive the corresponding screw 44 and fixed rod 90. The series of sleeves on the screw and the corresponding series of sleeves 96 on the rod, together with the two end members 97, are interconnected in a unitary manner by frame work that includes diagonal frame members 98 (Fig. 15). United with this framework is a guard arm 99 adjacent each rack unit 40 to protect the cdrresponding screw 44 from accidental impact by the racked stands or pipe. At

amass least one of the sleeves 95 is internally threaded for engagement with the threads of the corresponding screw; 44 to serve as a traveling nut for moving the carriage assembly and thereby moving the corresponding row of rack units 40 in unison. I

As shown in Fig. 13, the two screws 44 are journaled in bearings 100 on the derrick and are provided with bevel gears 101. The two bevel gears 101 mesh with corresponding bevel gears 102 that are actuated by an up right drive shaft 103. The lower end of the drive shaft 103 is actuated by a motor 104 ,(Fig. 2) on the derrick floor. Thus energization of the motor 104 causes both of the carriage assemblies to move in unison. v

For energization of the racking mechanism of the rack units 40 when the rack units are at the upper receiving station, a suitable motor 108 may be mounted on a horizontal hollow beam 109 that extends parallel to the two screws 44 between the two levels of the two carriage assemblies. The motor 108 is operatively connected to a longitudinal shaft 110 inside the hollow beam and this shaft in turn is operatively connected to two short counter shafts 111 each of which carries a driving bevel gear 112 outside the hollow beam. One of these driving bevel gears 112 is positioned to actuate the mechanism of an upper row rack unit 40 at the receiving station and the other positioned to actuate the corresponding lower row racking unit 40 at the receiving station. Each of the two driving bevel gears 112 is operatively connected with the corresponding counter shaft 111 by means of an electrically actuated clutch 113 which effects an operative connection only when desired. When the motor 108 is not energized, each of the driving bevel gears 112 is freely rotatable.

Each of the rack units 40 has a shaft 116 with a bevel gear 117 thereon positioned to cooperate with the corresponding driving bevel gear 112 that is driven by the motor 108. Thus, as may be seen in Fig. 11, when a rack unit 40 of the upper row is swung downward from its idle vertical p-osistion to its horizontal racking position, the bevel gear 117 of the unit is brought into mesh with the corresponding driving bevel gear 112 for actuation of the rack mechanism of the rack unit. The shaft 116 of each rack unit that carries the bevel gear 117 is operatively connected by irreversible worm gearing to a sprocket 118 for actuating the sprocket chain 42 of the unit. As best shown in Fig. 6, the sprocket chain 42 passes around the drive sprocket 118 and also around an idler sprocket 119 which is mounted on a shaft 102 at the outer receiving end of the rack unit.

The various pipe engaging fingers 41 carried by the sprocket chain 42 are continually urged outward away from the sprocket chain by concealed springs so that each finger tends to take an extended position at which a stop shoulder 121 of the finger backs against the sprocket chain, the sprocket chain serving as a stop to limit the outward movement of the fingen. Each of the rack units 40 has an operating side where the fingers 41 are fully extended to engage stands S of pipe and has a blind side where the fingers are retracted. On the blind side of each rack unit is guard plate 122 positioned adjacent the sprocket chain 42 to serve as means to cause the fingers 41 to be folded back against the sprocket chain in opposition to the concealed springs that are associated with the fingers.

The two rows of upper rack units 40 differ with respect to their operating sides. Thus, as viewed in Fig. 2, the fingers 41 of the upper row of rack units 40 extend to the right, the left sides of the units being the blind sides, and the fingers 41 of the lower row extend to the left, the right sides of the lower row of units being the blind sides.

The pipe shifting means As heretofore stated, the pipe shifting means 50 includes a box-like housing 52 that is mounted on a cantilever beam 53 for longitudinal reciprocation thereon. As

shown in Figs. 10 and 11, the cantilever beam 53 may be of hollow construction and may incorporate suitable rollers for supporting the surrounding housing 52 in a freely movable manner. In the construction shown, the rollers for cooperation with the housing 52 include upper pairs of rollers 125 on spaced axles 126, lower pairs of rollers 127 on lower spaced axles 128 and spaced pairs of side rollers 129 journaled in side flanges 130 of the hollow beam.

The longitudinal movements of the housing 52 on the beam 53 are controlled by a power cylinder 134 that is suitably mounted on the upper side of the housing. The power cylinder 134 has a rearwardly extending piston rod 135 which is connected to a fixed pin 136 at the fixed end of the beam 53.

The previously mentioned book 55 that is adapted to releasably engage stands S of pipe is mounted on a pivot 137 and has an integral operating arm 138. For actuation of the hook 55, a power cylinder 140 is pivotally mounted on the upper side of the housing 52 by suitable pivot means 141. The power cylinder 140 has a forwardly extending piston rod 142 that is pivotally connected by a pin 143 to the end of the operating arm 138. Extension of the piston rod 142 will cause the hook 55 to swing around a stand S of pipe and hold the stand in confinement against the side of the housing 52 as shown in full lines in Fig. 6; and retraction of the piston rod 142 will swing the hook out of the way into the retracted position shown in dotted lines in Fig. 6.

Preferably the cantilever beam 53 is provided with a retractable bar or auxiliary finger 147 which serves a purpose to be explained later. The auxiliary finger 1'47 extends through a slot 148 in the side of the reciprocative housing 52 and at its inner end is slidingly mounted in a guide channel 149 inside the beam 53. The finger 147 is controlled by a pivotally mounted solenoid 150 inside the beam which may be energized to cause the finger to retract. A concealed spring inside the solenoid structure urges the finger to its normal outward position when the solenoid is not energized. The solenoid is operatively connected to one arm of a lever 151 that is mounted on a suitable pivot means 152. The other arm of the lever 151 has a slot 153 to slidingly engage a headed pin 154 on the inner end of the finger 147. It is apparent that energization of the solenoid to retract its pivotal connection with the lever 151 will cause the finger 147 to be drawn into the beam 53. p

The various power cylinders associated with the rack units 40 and the two power cylinders of the pipe shifting means 50 may be either pneumatic or hydraulic and may be remotely controlled in various ways well known in the art. Preferably the various power cylinders are operated by compressed air.

Operation When a stand of pipe is unscrewed from the drill stem in the procedure of withdrawing the drill stem from the well bore, the elevator 28 is raised by the traveling block 29 to bring the lower end of the stand of pipe to an elevation just clear of the upper end of the guide chute 45. The power cylinder 134 of the pipe shifting means 50 is actuated to shift the reciprocative housing 52 outward on the cantilever beam 53, the hook 55 on the housing thus cause the suspended stand of pipe to be displaced towards the receiving stations of the lower support units 32 and the upper rack units 40. As the pipe shifting means 50 retracts in this manner to displace the suspended standcfpipe, the elevator 28 is lowered to bring the bottom end of the stand of pipe into contact with. the guide chute 45 and with continued lowering of the elevator the lower end of the pipe slides down the guide chute onto the upwardly directed boss 36 of the first support element 34 on the particular lower support unit 32 that is at the receiving station.

As the upper portion of the stand of pipe approaches the receiving end of the particular upper rack unit 40 that is at the upper receiving station, the sprocket chain 42 of the rack unit is actuated to advance one step in the racking direction of the chain so that one of the fingers 41 carried by the chain swings into engagement with the approaching stand of pipe as shown in Fig. 7. In the course of this movement of the stand of pipe into position to be engaged by the racking finger 41, the auxiliary finger 147 is momentarily retracted out of the path of movement of the stand of pipe to avoid interference with the movement. The finger 147 then extends again to its normal position. With the laterally shifted stand of pipe efi'ectively secured in racked position, the power cylinder 140 is energized to swing the hook 55 to its retracted position for repetition of the cycle of operation of the pipe shifting means 50.

As may be seen in Fig. 2, the operating side of each of the rack units 40 in the lower row, i. e., the side to which the fingers 41 extend for racking the pipe, is on the side towards the pipe shifting means 50. As may be understood by referring to Fig. 6, in these instances in which the operating side of a rack unit is on the side towards the pipe shifting means 50, the pipe shifting means cooperates with the fingers 41 to retain the stands of pipe in racked positions and the retractable finger 147 on the beam 53 is not necessary. On the other hand, the operating or racking sides of the rack units 40 in the upper row are on the sides away from the pipe shifting means Stl. Moreover, when one of these upper rack units is at the upper receiving station, it is positioned directly above the pipe shifting means 50 as may be seen in Fig. 8. The pipe shifting means 50, therefore, does not cooperate with the upper row of rack units 40 to confine the racked stands of pipe. Fig. 8 shows that the extent and curvature of the fingers 41 is such that the fingers adequately support the slightly leaning stands of pipe only after the fingers are advanced a second step from the receiving end of the rack unit. At the first pipe engaging step of a finger 41, a racking finger 41 requires the cooperation of the auxiliary finger 147. Thus, in Fig. 8 the extended auxiliary finger 147 cooperates with the racking finger 41 at the first racking position of the finger to form a cradle for the leaning stand of pipe.

The actuation of the sprocket chain 42 of the rack unit by one step brings a new finger 41 in position to receive the next succeeding pipe that is to .be racked in the same row, and the corresponding lower support unit 32 is actuated by energization of the motor 79 to shift the series of support elements 34 one stepin preparation for receiving the next stand of pipe.

When a row of stands of pipe has been completed in a pair of cooperating lower support units 32 and upper rack units 40, the drive shaft 86 of the motor 79 is reached to disengage the conical clutch member 85 from the clutch socket 84 of the lower support unit at the receiving station. The motor 66 is then energized to operate the screw 43 for shifting the carriage 70 to bring the next lower support unit 32 to the lower receiving station. In like manner, the motor 104 is energized to actuate the two upper carriage assemblies to shift sufficiently to bring the next rack unit 40 into position at the upper receiving station. When the shifting of the two upper carriage assemblies icarries a bevel gear 117 of a loaded rack unit 40 out of engagement with the corresponding driving bevel gear 112 at the receiving station, the driving bevel gear is ,not clutched and hence rotatesfreely to permit the disengagement. 1 Y

The next rack unit 40 is then moved from its 'vert ical idle position to its horizontal racking position by energization of the corresponding power cylinder 91. As a rack unit 40 reaches its horizontal position, the .corresponding bevel gear 117 carried by the rack unit is brought into operative mesh with the corresponding driving bevel bear 112. p

In the reverse procedure of returning stands .of pipe to the drill stem, the pipe shifting means 50 is first retracted to the position shown in Fig. 7 and the power cylinder 14% is actuated to extend the piston rod 142 to swing the hook 55 into position to engage the outermost stand of pipe at the receiving stations. The motor 108 is then energized to actuate the corresponding sprocket chain by one step in the unracking direction and the pipe shifting means 50 is then actuated by the power cylinder 13-4 to shift outward to move the upper end of the stand of pipe into the region of the axis of the well bore where the upper end may be engaged by the elevator 28. The auxiliary finger 147 is momentarily retracted to avoid interference with the unracking of the stand of pipe. The power cylinder of the pipe shifting means 50 is actuated to retract the hook 55 thereby to release the stand of pipe to the elevator 28 and then the elevator is raised by the traveling crown block. The upward movement of the elevator drags the lower end of the stand of pipe up the guide chute 45 until the lower end of the pipe swings clear of the guide chute. The elevator may then be lowered to permit the suspended stand of pipe to be screwed onto the drill stem in the bore hole.

it will be readily apparent to those skilled in the art that the described steps in the operation of the apparatus may be performed automatically if desired, thereby to relieve the operator of the burden of initiating tahe operation of each component of the apparatus in the sequence. Figs. 3 and 4 show, by way of example, a switch in the circuit of the motor 66 for automatically stopping the carriage 649 as each successive lower supporting unit 32 moves into position at the lower receiving station. The switch 160 is mounted on a fixed bracket 161 adjacent the path of travel of the carriage 6t) and an operating finger 162 is positioned on the carriage opposite each of the lower support units 32 to operate the switch 160 and thereby break the motor circuit. Thus the motor may be energized to cause the carriage to travel and the carriage will be automatically stopped when the next lower supporting unit 32 reaches the receiving station.

In like manner, each of the lower support units 32 may be provided with a switch 164 in the circuit of the motor 79 to automatically de-energize the motor when one step in the actuation of the series of support elements 34 has been completed. Each of the support elements 34 has a laterally extending lug 165 (Fig. 3) to operate the switch 164 as the support element reaches the end of one step of advancement of the series of support elements.

For similar control of the upper rack units 40, a pair of stationary limit switches 168 and 169 (Figs. 11 and 15) may be positioned to cooperate with the upper row of power cylinders 91 and a similar pair of limit switches may be positioned in fixed positions to cooperate with the lower row of power cylinders 91. One of the two limit switches 168 and 169 is used for each direction of travel of the corresponding carriage assembly and is positioned and adapted to break the circuit of the motor 104 in response to contact by the rear end of a power cylinder 91.

The step-by-step actuation of the sprocket chain 42 of each rack unit 40 may be controlled by a switch 171 (Fig. 6) which is adapted for actuation by a series of spaced lugs 172 on the sprocket chain 42. When the motor 108 is energized to advance the sprocket chain 42, one of the lugs 172 operates the switch 171 at the end of the step of advance, thereby to break the circuit of the motor.

As shown in Fig. 10, the cantilever beam 53 may be provided with two switches 174 and 175, each having an operating finger 176 positioned in the path of movement of the side wall of the reciprocative housing 52, As shown in Fig. 6, the two switches 174 and 175 are spaced apart longitudinally of the beam 53. When the power cylinder 134 is energized to shift the pipe shifting means 50 outward, eventually the housing 52 clears and releases the switch 174 to cause operation of the valve controlling the power cylinder 140, so that the power cylinder 140 will be energized to swing the hook 55 from its retracted position to a position engaging and confining a stand of pipe. At the end of the return or retracting movement of the housing 52, the housing operates the second switch 175 to cause energization of the power cylinder 140 to retract the hook 55 out of engagement with the pipe. The circuits of these two switches 174 and 175 with respect to the operation of the power cylinder 140 are also suitably adapted also to cause automatic operation of the hook 55 in the unracking opera tion of the apparatus.

Mounted inside the housing 52 is a concealed switch 178 (Fig. 6) which is adapted to be operated by a fixed pin 179 on the side of the beam 53. In the course of the retraction movement of the housing 52, the switch 178 is operated by the fixed pin 179 to cause momentary energization of the solenoid 150 thereby to retract the auxiliary finger 147 momentarily to clear the path of a stand of pipe being shifted by the hook 55. If desired, the switch 178 may also be given a second function of automatically closing the circuit of the motor 108 to cause the sprocket chain 42 of the unit at the receiving station to initiate operation for advancement by one step of the pipe engaging fingers 41 as the pipe shifting means 50 brings the new stand of pipe to the receiving end of the rack unit.

My description in detail of a selected embodiment of the invention will suggest to those skilled in the art various changes, substitutions and other departures from my disclosure that properly lie within the spirit and scope of the appended claims.

Having described my invention, 1 claim:

1. Apparatus of the character described for racking and unracking stands of pipe adjacent a well bore, said apparatus having in combination: a plurality of lower support units to support a corresponding plurality of rows of stands of pipe, each of said units having one end adapted to receive the lower ends of stands of pipe, each of said units being adapted to shift the lower ends of the stands of pipe successively to or from its receiving end; a corresponding plurality of upper rack units to engage upper portions of the rows of stands of pipe on said lower support units, each of said rack units having one end adapted to receive stands of pipe from the well bore, each of said rack units being adapted to shift the stands of pipe successively to or from its receiving end; and power means to actuate said support units and said rack units for racking and unracking stands of pipe.

2. Apparatus as set forth in claim 1, which includes power-actuated means to shift stands of pipe back and forth between the receiving ends of said units and the region of the axis of the well bore.

3. Apparatus as set forth in claim 1 which includes means to guide the lower ends of the stands of pipe from the region of the axis of the well bore to said lower support units whereby the stands of pipe may be lifted from the well bore and then lowered into engagement with said guide means for lateral displacement to said support units.

4. Apparatus as set forth in claim 3 which includes means to displace the upper portions of the stands of pin; away rom he resins 9f e. s. of th e l here ts stqss is uepa r u s.

5. Apparatus as set forth in claim 1 which includes means to move said lower support units selectively to a receiving station near the well bore for receiving the stands of pipe.

6. Apparatus as set forth in claim 5 which includes means to move said upper rack units selectively to a receiving station for receiving the upper portions of stands of pipe.

7. Apparatus of the character described for racking and unracking stands of pipe adjacent a well bore, said apparatus having in combination: a plurality of lower support units, each having one end adapted to receive pipe, said support units being movable in succession to a receiving station to receive pipe from the well bore or to relinquish pipe for return to the well bore; a row of support elements on each of said units to support the lower ends of a corresponding row of stands of pipe, said elements being movable on the unit to and from said receiving end in succession to receive or relinquish the lower ends of said stands of pipe; power-actuated means to move said support units individually to and from said receiving station and to move support elements on each support unit to and from said receiving end of the support unit; and upper rack means to stabilize the stands of pipe on said support units.

8. Apparatus as set forth in claim 7 in which said lower supportunits are interconnected to move in unison relative to said receiving station.

9. Apparatus as set forth in claim 8 which includes a carriage on which said support units are mounted and which includes a track for said carriage.

10. Apparatus as set forth in claim 7 which includes means to displace the lower end of a stand of pipe from the region of the axis of the well bore to said end of a support at said receiving station.

ll. Apparatus as set forth in claim 10 in which said guide means provides a downwardly inclined guide surface for sliding contact by the lower ends of the stands of pipe.

12. Apparatus as set forth in claim 7 in which said upper rack means comprises a plurality of rack units corresponding to said lower support units.

13. Apparatus as set forth in claim 12 in which said upper rack. units are movable in succession to an upper receiving station corresponding to said lower recei ing: station; and which include power means to move said upper rack units to and from said upper receiving station.

14. Apparatus as set forth in claim 7 which includes lower means to displace the lower end of a stand of pipe from the region of the axis of the well bore to the receiving end of a support unit at said receiving station; and includes upper means to displace the upper portions of the stands of pipe from the region of the axis of the well bore into engagement with said upper rack means.

15. In apparatus of the character described for racking and unracking stands of pipe adjacent a well bore, the combination of: a plurality of support units to support a corresponding plurality of rows of stands of pipe, each of said units having one end adapted to receive the lower ends of stands of pipe, said units being movable in succession to a receiving station to receive pipe from the well bore or to relinquish pipe for return to the well bore; a row of support elements on each of said units to support the lower ends of a corresponding row of stands of pipe, said elements being flexibly interconnected for movement in unison to permit movement of the elements successively to or from said receiving end of the support unit; and power means to move said support units in turn to said receiving station and to move said elements on each unit to and from the receiving end of the unit.

16. Apparatus as set forth in claim 15 in which each of said support elements is shaped to extend into the lower end of a stand of pipe.

17. Apparatus as set forth in claim 16 in which each of said support elements has a tapered projection for engagement with the lower end of a stand of pipe.

18. Apparatus as set forth in claim 17 in which said support elements are linked together on each of said lower support units and each unit provides a guideway for movement of the linked elements.

19. Apparatus as set forth in claim 18 in which the series of linked elements on each unit are movable in a path extending longitudinally of the top of the unit and turning downward at the receiving end of the unit.

20. Apparatus as set forth in claim 19 which includes a wheel member journaled at said end of each support unit to engage the linked elements in the manner of a sprocket Wheel engaging a sprocket chain.

21. Apparatus as set forth in claim 15 in which said plurality of units are mounted on a carriage and said power means moves said carriage.

22. In apparatus of the character described for racking and unracking stands of pipe adjacent a well bore, the combination of: lower support means to support the lower end of rows of stands of pipe, said means being movable to carry such row of pipe in a path laterally of the row to position the rows successively with one end of each positioned row at a lower receiving station adjacent the bore hole, said means being movable to load and unload each row of pipe progressively from the end of the row at said lower station; upper rack means to en gage upper portions of the same rows of stands of pipe to stabilize the rows of stands of pipe on said lower support means, said upper rack means being movable laterally of the rows to shift the upper portions of the rows of pipe to position the rows successively with one end of each positioned row at an upper receiving station corresponding to said lower receiving station, said rack means being movable to load and unload each row of pipe progressively from the end of the row at said upper station.

23. Apparatus as set forth in claim 22 which includes means to displace the lower ends of said stands of pipe from the region of the axis of the well bore to said lower receiving station.

24. Apparatus as set forth in claim 22 which includes power-actuated means to shift upper portions of said stands of pipe from the region of the axis of the well bore to said upper receiving station.

25. Apparatus as set forth in claim '24 which includes means to displace the lower ends of said stands of pipe from the region of the axis of the well bore to said lower receiving station.

26. In apparatus of the character described for racking and unracking stands of pipe adjacent a well bore, the combination of: lower support means to support the lower ends of rows of stands of pipe, said means being movable relative to a lower receiving station near the bore hole to load and unload each row of pipe progressively at the receiving station; a plurality of upper rack units, each corresponding to a row of stands of pipe on said lower support means, said upper rack units being movable relative to an upper receiving station corresponding to said lower receiving station, each of said rack units having one end to receive or to relinquish stands of pipe at said upper receiving station; a series of pipe engagement members movably mounted on each of said rack units to engage or disengage the stands of pipe to progressively rack or unrack the rows of pipe; and power means to move said rack units relative to said upper station and to move said engagement members on each rack unit relative to said end of the rack unit.

27. Apparatus as set forth in claim 26 in which said engagement members on each rack unit are flexibly connected together for movement in unison by the power means.

28. Apparatus as set forth in claim 26 in which said engagement members are incorporated in a sprocket driven chain.

29. Apparatus set forth in claim 28 which includes power-actuated means to displace the stands of pipe from the region of the axis of the well bore to said upper receiving station for engagement by said rack units.

30. In apparatus of the character described for racking and unracking stands of pipe adjacent a well bore, the combination of: a plurality of elevated rack units to engage and stabilize the upper portions of upright stands of pipe, each of said rack units having a receiving end to receive stands of pipe from the well bore and to relinquish the stands of pipe for return to the well bore, each of said units being adapted to shift stands of pipe successively to and from said receiving end; and power means to actuate said rack units and to shift the units successively to an upper receiving station for receiving stands of pipe from the well bore or for relinquishing the stands of pipe for return to the well bore/ 31. Apparatus as set forth in claim 30 in which each of said units has a series of pipe engagement members flexibly interconnected for movement in unison to move stands of pipe towards and away from said ends of the unit.

32. Apparatus as set forth in claim 31 in which said rack units are pivotally mounted and are power-actuated to swing between a substantially vertical retracted idle position and a substantially horizontal racking position.

33. In apparatus of the character described for rack ing and unracking stands of pipe adjacent a Well bore, the combination of: a plurality of elevated rack units to engage and stabilize the upper portions of upright stands of pipe, each of said rack units having a receiving end adapted to receive stands of pipe from the well bore and to relinquish the stands of pipe for return to the Well bore, each of said units being movable to shift stands of pipe successively to and from said receiving end; means to displace the upper portions of stands of pipe from the region of the well bore to said receiving ends of the rack units; and power means to energize each of said rack units to engage a stand of pipe in response to displacement of the stand of pipe towards the rack unit by said displacement means.

References Cited in the file of this patent UNITED STATES PATENTS 1,668,995 Woolever May 8, 1928 2,006,844 Smith July 2, 1935 2,423,169 Bennett July 1, 1947 2,628,725 Stone Feb. 17, 1953 

